1. Field of the Invention
The present invention relates to short-range wireless communication systems, and more particularly to systems utilizing inductive coupling.
2. Discussion of the Related Art
When using a telephone, continually holding the handset to one""s ear can be awkward. Also, holding the telephone interferes with the use of both hands for other work while trying to talk. In particular, the use of cellular telephones, which has increased dramatically, can interfere with the user""s proper operation of an automobile. Various techniques have been used to overcome these difficulties.
Speakerphones allow one to talk while roaming around a room and using one""s hands. However, speaker volume can disturb others around the user. They also cannot be used in close proximity to other speakerphones due to interference. They have limited privacy since the speaker broadcasts the conversation to all within earshot. Typically, the user must speak more loudly than normal to have proper reception at the microphone. Also, they tend to have poor sound quality because the user is not near the microphone and acoustics in the room are poor.
Headsets have been another way to free up the hands of a telephone user. Typically, the headset includes an adjustable strap extending across the user""s head to hold the headset in place, at least one headphone located by the user""s ear, and a microphone which extends from the headset along and around the user""s face to be positioned in front of the user""s mouth. The headset is attached by a wire to the telephone. Headsets have the disadvantages of being bulky and somewhat awkward to use. Although they permit hands free use of the telephone, the user has limited mobility due to the connecting wire.
Wireless headsets have also been developed which eliminate the connecting wire to the telephone. The wireless headset uses radio frequency (RF) technology or infrared technology for communicating between the headset and a base unit connected to the telephone. The need for communications circuitry and sufficient power to communicate with the base unit increases the bulk and weight of the headset. This increased weight can become tiresome for the user. One alternative has been to attach the headset by a wire to a transmitting unit worn on the belt of the user. As with wired headsets, the wire can become inconvenient and interfere with other actions by the user. Significant interference rejection circuitry is also needed when multiple wireless headsets are used in close proximity.
Therefore, a wireless communication system for telephones is desired with will provide greater convenience and comfort for the user.
The deficiencies of prior art systems are overcome by the present invention which, in one aspect, includes a short-range, wireless communication system including a miniaturized portable transceiver and a base unit transceiver. The miniaturized portable transceiver sends and receives information through magnetic induction to the base unit, which may also be portable. Similarly, the base unit sends and receives information through magnetic induction to the portable transceiver. The information can be voice, data, music, or video. Use of magnetic induction fields reduces the power requirements and thus allows a smaller size and greater convenience.
In another aspect of the present invention, the base unit may include multiple, orthogonally arranged transducers for generating multiple magnetic fields. The multiple fields substantially eliminates mutual inductance nulls between the base unit and portable unit which result at certain positions in a generated field. In another aspect of the present invention, the multiple transducers may be selectively operated based upon a strongest signal, in order to limit power consumption.
In another aspect of the present invention, a headset contains the miniaturized transceiver which communicates with the base unit through magnetic induction fields. The information sent between the headset and the base unit may be voice or data. In another aspect of the present invention, the headset may be of the concha type in which the speaker fits into the user""s ear without a strap across the head and the transceiving transducer is encapsulated into the microphone boom which is short and straight along the user""s cheek. In another aspect of the invention, the base unit may be a portable telephone, which can be attached to the user, to further transmit communications from the wireless communication system to a cellular telephone network or a cordless telephone unit.
In another aspect of the invention, the headset may fit in a receptacle in the portable base unit in order to recharge the battery in the headset. In another aspect of the invention, the battery may be recharged via the magnetic inductive link between the base unit and the headset.
With these and other objects, advantages and features of the invention that may become apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the invention, the appended claims and the several drawings attached hereto.